KR102573101B1 - Digital signal integrity improving structures through common-signal rejection and phase recovery for super-high speed digital signal transmission - Google Patents

Abstract

The present invention proposes a high-speed digital signal quality enhancement structure. The structure of the present invention is a first unit structure of the same or different shape arranged to face each other on the left and right in the longitudinal direction of the balance line centered on the type 1 balance line (CPS) or the type 2 balance line (PSL) formed on the substrate. and a second unit structure. And any one unit structure has a first side close to the balance line and having a straight or curved shape, a second side facing the first side, and left and right sides connecting the first side and the second side It is a composition that includes Here, the width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope, and the width from the first side to the second side continuously changes or is discontinuous. is configured to change to When the structure of the present invention is disposed around the balanced line, there is an advantage in that the distorted phase can be independently restored while suppressing the common signal in a frequency band of up to 40 GHz or higher.

Description

Signal quality improvement structures through common-signal rejection and phase recovery for super-high speed digital signal transmission}

The present invention relates to an ultra-high-speed digital signal quality enhancement structure capable of self-restoring a distorted phase while suppressing a common signal in a frequency band of up to 40 GHz or higher.

Ultra-high transmission speed is required for high-capacity digital data transmission for 5G and next-generation communications. Up to now, differential lines are used to transmit high-speed digital signals. However, differential lines cause signal skew due to the length difference between two signal lines, unequal electromagnetic interference (EMI) due to adjacent lines, and electromagnetic (EM) between signal lines when a phase difference between two signal lines occurs that is out of 180°. It is impossible to use in a frequency band of 10 GHz or higher due to various problems such as nonlinear distortion of the phase due to coupling and phase difference caused by the fiber weave of the FR4 substrate.

In addition, these problems cause common signals that are very fatal to digital circuit operation. The common signal has a component of a frequency band that is mainly higher than that of the differential signal, and is a main cause of electromagnetic interference (EMI), and adversely affects the operation of a circuit receiving the signal. Therefore, for the normal operation of the digital circuit, it is necessary to suppress the magnitude of the common signal, and for this purpose, a filter for suppressing the common signal is required.

Most commercially available common signal suppression filters are a method in which two signal lines connected to a differential line are wound around a ferrite core, and a signal is suppressed through a magnetic field generated from the ferrite core. However, since the impedance of the inductor generated by winding the two signal lines around the ferrite core increases up to a specific frequency and becomes affected by parasitic components as the frequency increases, the frequency band capable of suppressing the common signal is limited to about 10 GHz or less.

In addition, the common signal suppression filter published in the papers so far is a method using various types of resonance structures that deform the ground plane under the differential line. However, since it is a narrow band and has a maximum frequency of about 15 GHz or less, it is not suitable for use in high-speed digital communication for the next generation.

Therefore, since the common signal suppression filter proposed or used so far has a limited frequency band within about 15 GHz, improvement of ultra-wideband common signal suppression performance is urgently needed for high-speed digital signal transmission of tens or hundreds of Gbps in the future.

Korean Registered Patent No. 10-0771529 (registered on October 24, 2007) Korean Registered Patent No. 10-1157825 (2012. 06. 13. Registration)

An object of the present invention was made to solve the above problems, while minimizing the effect on the differential signal required for ultra-high-speed digital signal transmission, while removing or suppressing the common signal in a frequency band up to a predetermined or higher level (ie, 40 GHz or higher). At the same time, the distorted phase is to provide an ultra-high-speed digital signal quality enhancement structure capable of restoring itself.

Another object of the present invention is to remove the common signal and phase it when a digital signal passing through a differential line-based circuit is distorted and a common signal is generated and nonlinear phase distortion occurs due to a length difference between two signal lines and electromagnetic coupling between signal lines. It is to provide an ultra-high-speed digital signal quality improvement structure that enables ultra-high-speed digital communication by enabling restoration.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

An ultra-high-speed digital signal quality improvement structure according to an embodiment of the present invention for achieving the above object is a first-type balanced line (CPS: Coplanar stripline) or a second-type balanced line (PSL: Parallel stripline) formed on a substrate. A structure that is arranged to face each other on the left and right in the longitudinal direction of the balance line centered on, and removes the common signal component of the digital signal and restores the distorted phase at the same time. It includes two unit structures, and any one unit structure includes a first side that is close to the balance line and may have a straight or curved shape, a second side opposite to the first side, and a first side that is close to the balance line. It includes left and right sides connecting two sides, the width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope from the first side to the second side. The width of is configured to change continuously or change discontinuously.

The structure is entirely composed of conductors, or a portion of the conductor inside the structure is removed.

Each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined distance.

The second sides of the first unit structure and the second unit structure are connected to or separated from the ground plane formed on the substrate.

At least one or more structures are arranged along the length direction of the balance line, and the arranged structures are structures having the same shape or a combination of structures having different shapes.

Structures are arranged periodically or non-periodically along the length direction of the balance line.

A high-speed digital signal quality enhancement structure according to another embodiment of the present invention, in a structure including a transition structure connecting a balance line to a differential line, removes a common signal component of a digital signal and restores a distorted phase of the balance line A structure arranged to face each other on the left and right in the longitudinal direction of the equilibrium line centered on, the structure includes a first unit structure and a second unit structure having the same or different shapes, and any one unit structure is It includes a first side that is close to the track and may have a straight or curved shape, a second side facing the first side, and left and right sides connecting the first side and the second side, and the width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope, and the width from the first side to the second side continuously changes or discontinuously changes.

The structure is entirely composed of conductors, or a portion of the conductor inside the structure is removed.

Each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined distance.

The second sides of the first unit structure and the second unit structure are connected to or separated from the ground plane formed on the substrate.

At least one structure is arranged along the length direction of the balance line, and the arranged structure may be a combination of a structure having the same shape or a structure having a different shape, and may be periodic or non-periodic along the length direction of the balance line. are arranged as

A surface-mounted digital signal quality enhancement structure according to another embodiment of the present invention includes a first substrate having a differential line; A second substrate having a balance line, wherein the structures are arranged to face each other on the left and right in the longitudinal direction of the balance line with the balance line as a center, and the structures have the same or different shapes. It includes a first unit structure and a second unit structure, and any one unit structure includes a first side that is close to the balance line and may have a straight or curved shape, a second side facing the first side, and the It includes left and right sides connecting the first side and the second side, the width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope and the first side The width from to the second side is configured to continuously change or discontinuously change.

The structure is entirely composed of conductors, or a portion of the conductor inside the structure is removed.

Each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined distance.

The second sides of the first unit structure and the second unit structure are connected to or separated from the ground plane formed on the substrate.

At least one structure is arranged along the length direction of the balance line, and the arranged structure may be a combination of a structure having the same shape or a structure having a different shape, and periodically or non-periodically along the length direction of the balance line. are arranged

According to the present invention, the common signal can be suppressed or removed in a frequency band of up to 40 GHz or higher, and the distorted phase can be restored by itself, so that the quality of the digital signal is greatly improved. Signals can be transmitted according to the ultra-high transmission speed.

According to the present invention, since it can be applied to a high-speed interface and chip, etc., an effect that can be easily applied to next-generation communication technology as well as 5th generation communication technology that needs to support high performance and ultra-wide frequency bandwidth can be expected.

According to the present invention, since the phase difference caused by the difference in the length of the differential line and the phase difference caused by the fiber weave can be recovered even on a general FR4 board, it is a low-cost PCB process, which is much improved compared to the conventional high-speed digital signal transmission is possible

According to the present invention, when applied to a differential line-based digital circuit board, the quality of a digital signal can be improved, and in particular, when applied to a transition structure connecting a balanced line to a differential line, a frequency band of up to 40 GHz or more can be obtained. This enables high-speed digital signal transmission.

1 is a diagram for explaining a difference in length of a differential line, which is an existing digital line.
2 is a graph showing the degree of phase distortion when a length compensation structure is applied when there is a difference in length between two signal lines of a differential line.
3 is a differential line structure.
FIG. 4 is an electric field distribution diagram for a differential signal in the differential line of FIG. 3 .
FIG. 5 is an electric field distribution diagram for a common signal in the differential line of FIG. 3 .
6 is a balanced line structure.
7 and 8 are diagrams of electric field distribution of a differential signal and electric field distribution of a common signal in a CPS line and a PSL line, which are balanced lines.
9 is a diagram showing a high-speed digital signal quality enhancement structure according to an embodiment of the present invention.
10 is a view showing an example in which unit structures of the present invention having various shapes are arranged on a substrate.
11 is a view showing a state in which the structure of the present invention is applied to a transition structure between a differential line and a balance line.
12 is a view showing a surface-mounted digital signal quality enhancement structure including the structure of the present invention.
13 is a graph showing EM simulation results when the structure of the present invention is applied to a Rogers 4003 8-mil substrate.
14 is a graph showing EM simulation results when the structure of the present invention is applied to a Duroid 5880 10mil substrate.

Since the present invention can apply various transformations and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, it should be understood that this is not intended to limit the specific embodiments of the present invention, and includes all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

Terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Spatially relative terms, such as below, beneath, lower, above, upper, etc., facilitate the correlation between one element or component and another element or component, as shown in the drawing. can be used to describe Spatially relative terms should be understood as encompassing different orientations of elements in use or operation in addition to the orientations shown in the figures. For example, when an element shown in the drawing is turned over, an element described as below or beneath another element may be placed above or above the other element. Accordingly, the exemplary term below may include both directions of down and above. Elements may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

An expression indicating a part such as "part" or "part" used in the present invention refers to a device in which a corresponding component may include a specific function, software that may include a specific function, or a device that may include a specific function and software, but cannot necessarily be limited to the expressed functions, which are provided only to help a more general understanding of the present invention, and those with ordinary knowledge in the field to which the present invention belongs If so, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and it will be said that not only the claims to be described later, but also all modifications equivalent or equivalent to these claims fall within the scope of the spirit of the present invention. .

Hereinafter, the present invention will be described in more detail based on the embodiments shown in the drawings.

Prior to explaining the present invention, a difference in length between two signal lines of a differential line and a nonlinear phase distortion phenomenon due to electromagnetic coupling between the two signal lines will be described. This is because the phase difference causes a common signal, and this common signal is the main cause of electromagnetic interference (EMI) that adversely affects circuit operation.

1 is a diagram for explaining a difference in length of a differential line, which is an existing digital line.

As shown in FIG. 1, when a difference in length between the two signal lines (eg, due to a curved portion due to rotation of the line) occurs (region a), a length compensation structure (region b) is applied to the relatively short signal line to phase compensating for the difference. In this case, nonlinear phase distortion occurs due to electromagnetic coupling between the two signal lines. Even if the line length is compensated as described above, the higher the frequency, the more the phase distortion worsens.

2 is a graph showing the degree of phase distortion when a length compensation structure is applied when there is a difference in length between two signal lines of a differential line. 2 is a 3D EM simulation result using an 8 mil thick Rogers 4003 substrate, (a) shows the distance between the position where the length difference occurred and the length compensation structure is 600 mil, (b) shows the position where the length difference occurred and the length compensation structure This is the case when the distance between them is 1000 mil.

Looking at this, it can be seen that the phase is distorted by more than 20 degrees after 20 GHz when the length difference is more than 30 mil. In addition, when a length difference of more than 60 mil occurs, when the distance to the length compensation structure is 1000 mil, it can be confirmed that the phase is distorted by more than 20 degrees after 11.7 GHz.

In this way, when a difference in length between two signal lines of a differential line occurs, as the frequency increases, the nonlinear phase distortion of the differential line intensifies, and it can be seen that it is impossible to recover the distorted phase with a simple length compensation structure.

On the other hand, when the FR4 board, which is widely used as a commercial digital circuit board in FIG. 1, is applied to the differential line, a phase difference occurs due to the weave structure of the constituent fibers of the FR4 board. That is, even if there is no difference in length between the two signal lines of the differential line, about 0 to 107 mil depending on the position and direction of the line per 1 inch (1000 mil) of the length of the signal line on the component fiber weave structure of the FR4 board (maximum differential line An effective length difference of about 10% of the length) occurs. Therefore, since the effective length difference between the two signal lines of the differential line may be different for each actual PCB, it is virtually impossible to predict and compensate for the value for each PCB.

3 is a differential line structure. 3, a dielectric substrate 1 having a height of h, and a first signal line 2 and a second signal line 3 capable of applying signals having opposite polarities to each other are disposed on top of the dielectric substrate 1, A ground plane 4 is formed at the lower end of the dielectric substrate 1 . The first signal line 2 and the second signal line 3 may be microstrip lines (MSL). Also, when a differential signal is applied, the first signal line 2 and the second signal line 3 have opposite polarities. For example, if the first signal line 2 is a negative line, the second signal line 3 may be a positive line. The first signal line 2 and the second signal line 3 have the same width w, and the first signal line 2 and the second signal line 3 are separated by a distance g.

FIG. 4 is an electric field distribution diagram for a case in which a differential signal is applied in the differential line of FIG. 3 . Looking at this, an electric field connecting between the two signal lines 2 and 3 exists, and each electric field is distributed between the two signal lines 2 and 3 and the ground plane 4. The two electric fields between the two signal lines 2 and 3 and the ground plane 4 are independent of each other. In particular, when there is a phase difference of 180° between the two signal lines (2,3) of the differential line, electromagnetic coupling between the two signal lines (2,3) causes nonlinear phase distortion, and when the operating frequency is 10 GHz or higher As the nonlinear phase distortion phenomenon intensifies, it is impossible to recover the phase of the differential line itself.

FIG. 5 is an electric field distribution diagram for a common signal in the differential line of FIG. 3 . Looking at this, as a case where signals of the same polarity are applied to the two signal lines 2 and 3, it is possible for a common signal to proceed independently through the two signal lines 2 and 3. Therefore, since it is impossible to suppress the common signal by itself, a separate filter for blocking the common signal is required.

6 shows a balanced line structure, wherein (a) is a Coplanar stripline (CPS) of type 1, and (b) is a parallel stripline of type 2 (PSL: Parallel stripline).

The characteristics of the balanced line are that it can transmit ultra-wideband differential signals, suppress electromagnetic interference from nearby lines, restore the phase on its own when a phase difference is out of 180° between two signal lines, and distribute the electric field and permittivity of the substrate. It is possible to calculate key parameters through analytical design considering , and features capable of improving performance through characteristic impedance change are provided. In the case of a type 2 balanced line PSL (Parallel strip line), it is possible to maintain signal characteristics even in a bent line.

As shown in (a) and (b) of FIG. 6, the balanced line does not have a separate ground plane, and the two signal lines become each other's ground line to transmit a differential signal.

Specifically, the CPS line 10 of FIG. 6 (a) has a dielectric substrate 11 having a predetermined height h and a first signal line 12 and a second signal line 13 having opposite polarities on top of the dielectric substrate 11. are placed The first signal line 12 and the second signal line 13 have the same width w, and the first signal line 12 and the second signal line 13 are separated by a distance g.

And the PSL line 20 of FIG. 6 (b) has a dielectric substrate 21 having a predetermined height h, a first signal line 22 is disposed on the top of the dielectric substrate 21, and a second signal line is placed on the bottom of the dielectric substrate 21 (23) is placed. The first signal line 22 and the second signal line 23 have opposite polarities and are disposed parallel to each other. The first signal line 22 and the second signal line 23 have the same width w.

Figure 7 (a) is the electric field distribution of the differential signal in the CPS line, Figure 7 (b) is the electric field distribution of the differential signal in the PSL line, Figure 8 (a) is the electric field distribution of the common signal in the CPS line, Figure 8 (b) is the electric field distribution of the common signal in the PSL line.

Referring to FIG. 7(a), an electric field directed from the second signal line 13 to the first signal line 12 is mainly formed. That is, the condition is that an electric field is always formed between the second signal line 13 and the first signal line 12 . Referring to FIG. 7( b ), an electric field directed from the second signal line 23 to the first signal line 22 is mainly formed. On the other hand, referring to FIG. 8(a) and FIG. 8(b) , only electric fields exiting from the first signal lines 12 and 22 and the second signal lines 13 and 23 exist.

In the case of such a balanced line, a common signal component can be suppressed to some extent due to structural characteristics, and a strong electromagnetic coupling exists between two signal lines to restore the phase of a distorted signal.

The present invention proposes a method of arranging a structure capable of self-phase restoration around a balanced line capable of suppressing or removing common signal components while minimizing the influence on differential signal components in a balanced line capable of transmitting digital signals at high speed.

9 is a diagram showing an example of a unit structure forming a high-speed digital signal quality improvement structure according to an embodiment of the present invention. As mentioned above, the structure of the present invention can suppress the progress of the common signal component while minimizing the effect on the differential signal component among the components of the digital signal, and at the same time provides a feature of self-restoring the distorted phase.

Referring to FIG. 9, the structure of the present invention is formed as a conductor on the upper or lower surface of a dielectric substrate and is centered on the first signal line 111 and the second signal line 112, which are balance lines 110 formed in the center of the substrate 100. are placed facing each other.

In the drawing, structures 200, 300, 400, and 500 having different shapes are exemplarily shown in regions I to IV along the length direction of the balance line 110, and each structure 200, 300, 400, and 500 includes first unit structures 200a, 300a, 400a, and 500a and second unit structures 200b, 300b, 400b, and 500b disposed facing each other with the balance line 110 in the center. The first unit structures 200a, 300a, 400a, and 500a and the second unit structures 200b, 300b, 400b, and 500b illustrated to face each other with the balance line 110 in the center may have the same or different shapes. may be arranged as a pair.

Each unit structure exemplified by the first to fourth structures 200, 300, 400, and 500 may be formed in various ways, but may be designed according to the following rules. Since the same rules apply to all, the first structure 200 will be described as an example.

Looking at any one of the illustrated unit structures 200a or 200b of the first structure 200, the first side (upper side) 201, which is close to the balance line 110 and has a straight or curved shape, the first side ( 201) and a second side (lower side) 202 facing each other, and left/right sides 203 and 204 connecting the first side 201 and the second side 202. The first side 201 may be formed with a smaller width than or the same width as the second side 202 . In addition, the left/right sides 203 and 204 have a linear or non-linear slope, and may be formed in a structure in which the width continuously changes or discontinuously changes from the first side 201 to the second side 202. there is. The continuous shape may be a straight or curved shape, and the discontinuous shape may be a stepped shape.

Meanwhile, as shown in FIG. 9 , any one structure 500 may have a shape in which an inner part of the conductor is empty.

Unit structures manufactured according to these design rules can be arranged according to the following rules on the balance line.

As shown in FIG. 9, the first unit structures 200a, 300a, 400a, 500a and the second unit structures 200b, 300b, 400b, 500b) each positioned facing each other. In FIG. 9, the first side is located on the side of the balance line 110 in the arrangement direction of the unit structure. The first side may be located on the same side of the substrate where the balance line 110 is formed, or at the top or bottom. At this time, the first sides of the facing unit structures are not connected to each other and are arranged at regular intervals. The second side may be connected to the ground plane 120 or may be arranged at regular intervals. In FIG. 9 , the type connected to the ground plane may be the first structure 200 , and the type separated at regular intervals may be the second to fourth structures 300 , 400 , and 500 .

One or several unit structures arranged continuously along the length direction of the balance line 110 may be arranged periodically or non-periodically, structures having different shapes may be arranged together, and structures may be arranged to overlap each other. can For example, in FIG. 9 , only the first structure 200 is continuously arranged, the first structure 200 and the second structure 300 are repeatedly arranged, or the first structure 200 and the second structure 300 are repeatedly arranged. ) -can be arranged in the order of the third structure 400.

Various examples in which the structure of the present invention is arranged around the balance line 110 can also be confirmed through FIG. 10 . 10 are views showing examples in which structures of the present invention having various shapes are arranged on a substrate.

Referring to FIG. 10(a), around the balance line 110 at the center of the substrate 100, structures 600a and 600b having the same shape are arranged symmetrically with each other. The first sides of the structures 600a and 600b facing each other are located at the lower end of the balance line 110 and are separated from each other at regular intervals, and the second sides are connected to the ground plane 120.

The structures 700a and 700b of FIG. 10(b) have a substantially flag shape. Referring to FIG. 10 (b), the first structure 700a and the second structure 700b are symmetrical to each other around the balance line 110, and are also arranged symmetrically along the length direction of the balance line 110. .

10(c) is an example in which the structures 800a and 800b are formed as a single structure in which trapezoidal unit structures are positioned to overlap a certain area along the length direction of the balance line 110.

10(d) shows an example in which the structure of the present invention is arranged in a PSL line. In FIG. 10(d), one structure 900a is located on the upper side of the substrate 100 with respect to the balance line 110, and the other structure 900b is located on the lower side of the substrate 100, and is symmetrical to each other. Also, the first sides of the structures 900a and 900b are separated from each other, and the second sides are connected to the ground plane 120 .

Previously, examples of arranging structures according to a certain rule on a substrate formed of only balanced lines have been described.

However, since the present invention can be applied to a line having both a differential line and a balanced line, it will be continued with reference to FIG. 11 .

11 is a diagram showing a state in which a structure of the present invention is applied to a transition structure between a differential line and a balance line. Here, the transition structure is disclosed in No. 10-2021-0138269 (transition structure for high-speed digital signal transmission and digital transmission line including the same) filed by the present applicant on October 18, 2021. The transition structure connects a balanced line to a differential line so that a digital signal can be transmitted at an ultra-high speed. It has features that enable common signal and electromagnetic interference (EMI) suppression and phase restoration. In addition, the balanced line may have various line impedances depending on circuit conditions.

Therefore, even the transition structure for ultra-high-speed digital signal transmission provides characteristics of common signal cancellation and phase restoration in an ultra-wideband, and common signal rejection performance may be about 5 to 10 dB in an operating frequency band of up to several tens of GHz or more. In other words, by additionally arranging the structure of the present invention around the balance line including the transition structure, the common signal rejection performance can be greatly improved in an ultra-wide frequency band.

11(a) to (d), the structure of the present invention is disposed around the balance line 2000 in the structure in which the differential line 1000 and the balance line 2000 are connected. In the structure of (a), the mountain-shaped structures are arranged to face each other, and the first side is located at the lower end of the balance line and is separated from each other. In the structure of (b), mountain-shaped structures are disposed around the balance line 2000 so as to face each other in a transition structure having a different shape, and the first side is spaced apart from the balance line. (c) and (d) are shapes in which two or more unit structures having different shapes are symmetrically arranged around the vertical direction of the balance line 2000 and further symmetrically arranged along the longitudinal direction of the balance line 2000. am.

In this way, the structure of the present invention can be applied to the periphery of the balance line in the structure that connects the differential line and the balance line of the circuit board with optimal performance, so that more common signals can be removed and the quality of the digital signal is improved. can make it

12 is a diagram illustrating a surface-mounted digital signal quality enhancement structure including the structure of the present invention. The structure of the transmission line of FIG. 12 is to be applied to an existing general digital circuit board.

Referring to this, a first substrate 1100 on which the differential line 1000 is formed and a second substrate 1300 connected through vias 1200 are included. In the second substrate 1300, the via 1200 structure is used to form a balance line 2000 connected to the differential line 1100 of the digital signal transmission/reception terminal, and face each other with the balance line 2000 as the center. A structure 200 is disposed.

That is, the second substrate 1300 is composed of the balance line 2000 and the structure 200 together in a module form, and thus is compatible with general digital transmission lines.

As the structure applied to the second substrate 1300, all structures of various shapes described above may be applied in addition to the structure shown in FIG. 12, and may also be implemented on a multilayer substrate.

Continuing to look at the performance evaluation of the structure of the present invention.

In the performance evaluation, common signal suppression performance and phase recovery performance were evaluated through 3D EM simulation when the structure of the present invention was applied to the transition structure for high-speed digital signal transmission filed by the present applicant. Furthermore, the structure of the present invention was implemented using the substrate, and performance similar to that of the simulation was confirmed by measuring with a 4-port network analyzer.

13 is a graph showing EM simulation results when the structure of the present invention is applied to a Rogers 4003 8-mil substrate. (a) is a graph showing the common signal suppression level, (b) is a graph showing the phase recovery level.

Looking at (a), it can be seen that a common signal of 7 dB or more is blocked in a frequency band of 2.4 GHz to 40 GHz or more, and a common signal of 10 dB or more is blocked in a frequency band of 11.4 GHz to 40 GHz or more. In this case, the attenuation of the differential signal is a maximum of 3.1 dB and an average of 1.1 dB up to 40 GHz, confirming that the transmission characteristics of the differential signal are excellent.

It can be seen that the phase recovery level of (b) is a case where there is a difference in length of 30 mil between the signal lines of the differential line, and the phase is restored within 20 degrees in a frequency band of 40 GHz or higher.

14 is a graph showing EM simulation results when the structure of the present invention is applied to a Duroid 5880 10 mil substrate.

Looking at (a), it can be seen that a common signal of 10 dB or more is blocked in a frequency band of 2.1 GHz to 40 GHz or more, and a common signal of 15 dB or more is blocked in a frequency band of 9.3 GHz to 40 GHz or more. In this case, the attenuation of the differential signal is a maximum of 3.2 dB and an average of 1.6 dB up to 40 GHz, confirming that the transfer characteristics of the differential signal are excellent.

It can be seen that the phase recovery level of (b) is a case where there is a 60 mil length difference between the signal lines of the differential line, and the phase is restored within 20 degrees in a frequency band of 40 GHz or higher.

In this way, when the structure of the present invention is applied around the balanced line, it is possible to block the common signal and restore its own phase in an ultra-wide band, thereby improving the quality of the digital signal and enabling transmission of the next generation ultra-high-speed digital signal. can

In addition, when the structure of the present invention is applied to a general FR4 board, it is possible to recover the phase difference caused by the difference in length of the differential line without being affected by the weave structure of the constituent fibers of the board, so that a low-cost PCB process can achieve high-speed digital signal transmission is possible.

In addition, when applied to a digital circuit board based on a differential line, the quality of a digital signal can be improved.

In addition, if the structure of the present invention is applied to a transition structure connecting a balanced line to a differential line, high-quality, high-speed digital signal transmission is possible in a frequency band of 40 GHz or higher.

Although the description has been made with reference to the illustrated embodiments of the present invention as described above, these are merely examples, and those skilled in the art to which the present invention belongs can variously It will be apparent that other embodiments that are variations, modifications and equivalents are possible. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: substrate
110: balanced line
120: ground plane
200, 300, 400, 500: structure of the present invention

Claims (17)

The differential signal component of the digital signal is It is a structure that removes common signal components and restores the distorted phase while affecting
The structure is
Including a first unit structure and a second unit structure having the same or different shapes,
Any one unit structure,
a first side close to the balance line and having a straight or curved shape;
a second side facing the first side; and
Including left and right sides connecting the first side and the second side,
The width of the first side is smaller than or equal to the width of the second side,
The left and right sides have a linear or non-linear slope and the width from the first side to the second side is configured to continuously change or discontinuously change, ultra-high-speed digital signal quality enhancement structure. According to claim 1,
The structure is entirely composed of a conductor, ultra-high-speed digital signal quality enhancement structure. According to claim 1,
The structure is composed of a state in which a portion of the inner conductor is removed, ultra-high-speed digital signal quality enhancement structure. According to claim 1,
Wherein each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined interval, ultra-high-speed digital signal quality enhancement structure. According to claim 1,
Second sides of the first unit structure and the second unit structure are connected to or spaced apart from the ground plane formed on the substrate, high-speed digital signal quality improvement structure. According to claim 1,
At least one structure is arranged along the length direction of the balance line,
The arrayed structure is a structure having the same shape or a structure having a different shape, ultra-high-speed digital signal quality improvement structure. According to claim 1,
Structures are arranged periodically or aperiodically along the length of the balance line, high-speed digital signal quality enhancement structure. In a structure including a transition structure connecting a balanced line to a differential line, the common signal component is removed while the differential signal component of the digital signal is minimally affected and the distorted phase is restored in the longitudinal direction of the balance line centered on the balance line. It is a structure arranged to face each other on the left and right of the reference,
The structure is
Including a first unit structure and a second unit structure having the same or different shapes,
Any one unit structure,
a first side close to the balance line and having a straight or curved shape;
a second side facing the first side; and
Including left and right sides connecting the first side and the second side,
The width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope, and the width from the first side to the second side continuously changes or discontinuously. Characterized in that configured to change, ultra-high-speed digital signal quality enhancement structure. According to claim 8,
The structure is composed entirely of conductors, or is composed of a state in which a portion of the inner conductor is removed, ultra-high-speed digital signal quality enhancement structure. According to claim 8,
Wherein each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined interval, ultra-high-speed digital signal quality enhancement structure. According to claim 8,
Second sides of the first unit structure and the second unit structure are connected to or spaced apart from a ground plane formed on a substrate, high-speed digital signal quality improvement structure. According to claim 8,
At least one structure is arranged along the length direction of the balance line,
The arrayed structures may be structures having the same shape or structures having different shapes,
An ultra-high-speed digital signal quality enhancement structure arranged periodically or aperiodically along the length direction of the balance line. A first substrate provided with a differential line;
Including a second substrate equipped with a balance line,
On the second substrate, structures are disposed to face each other on the left and right in the longitudinal direction of the balance line with the balance line as the center,
The structure is
Including a first unit structure and a second unit structure having the same or different shapes,
Any one unit structure,
a first side close to the balance line and having a straight or curved shape;
a second side facing the first side; and
Including left and right sides connecting the first side and the second side,
The width of the first side is smaller than or equal to the width of the second side, and the left and right sides have a linear or non-linear slope, and the width from the first side to the second side continuously changes or discontinuously. Characterized in that it is configured to change, surface-mounted ultra-high-speed digital signal quality enhancement structure. According to claim 13,
The structure is entirely composed of a conductor, or a surface-mounted ultra-high-speed digital signal quality enhancement structure configured in a state in which a portion of the inner conductor is removed. According to claim 13,
Wherein each first side of the first unit structure and the second unit structure are spaced apart from each other by a predetermined distance, the surface-mounted ultra-high-speed digital signal quality enhancement structure. According to claim 13,
Second sides of the first unit structure and the second unit structure are connected to or separated from a ground plane formed on the substrate, surface-mounted ultra-high-speed digital signal quality enhancement structure. According to claim 13,
At least one structure is arranged along the length direction of the balance line,
The arrayed structures may be structures having the same shape or structures having different shapes,
A surface-mounted ultra-high-speed digital signal quality enhancement structure arranged periodically or aperiodically along the length direction of the balance line.

Images